Reviewing All the Muscles You Have Studied So Far Which Ones Allow You to Look Up at the Ceiling

Learning Objectives

• Identify the axial muscles of the face up, caput, and cervix
• Place the movement and role of the confront, head, and neck muscles

The skeletal muscles are divided intoaxial (muscles of the body and caput) andappendicular (muscles of the arms and legs) categories. This system reflects the bones of the skeleton system, which are likewise arranged in this style. The centric muscles are grouped based on location, function, or both. Some of the axial muscles may seem to blur the boundaries considering they cross over to the appendicular skeleton. The kickoff group of the axial muscles you will review includes the muscles of the head and neck, so you volition review the muscles of the vertebral cavalcade, and finally yous will review the oblique and rectus muscles.

Muscles That Create Facial Expression

The origins of the muscles of facial expression are on the surface of the skull (remember, the origin of a muscle does non motion). The insertions of these muscles have fibers intertwined with connective tissue and the dermis of the skin. Considering the muscles insert in the skin rather than on bone, when they contract, the peel moves to create facial expression (Figure 1).

Figure 1. Muscles of Facial Expression. Many of the muscles of facial expression insert into the skin surrounding the eyelids, nose and oral cavity, producing facial expressions by moving the skin rather than basic.

Theorbicularis oris is a circular muscle that moves the lips, and theorbicularis oculi is a circular muscle that closes the heart. Theoccipitofrontalis muscle moves upwardly the scalp and eyebrows. The muscle has a frontal abdomen and an occipital (near the occipital bone on the posterior part of the skull) belly. In other words, there is a muscle on the forehead (frontalis) and 1 on the dorsum of the caput (occipitalis), but there is no muscle beyond the acme of the head. Instead, the two bellies are continued by a wide tendon called theepicranial aponeurosis, or galea aponeurosis (galea = "apple"). The physicians originally studying human beefcake thought the skull looked like an apple tree.

The bulk of the face is composed of thebuccinator muscle, which compresses the cheek. This muscle allows you to whistle, blow, and suck; and it contributes to the action of chewing. In that location are several small facial muscles, ane of which is thecorrugator supercilii, which is the prime mover of the eyebrows. Place your finger on your eyebrows at the point of the bridge of the olfactory organ. Raise your eyebrows as if y'all were surprised and lower your eyebrows as if you were frowning. With these movements, y'all tin can feel the action of the corrugator supercilli. Additional muscles of facial expression are presented in Tabular array i.

Table i. Muscles in Facial Expression
Motility	Target	Target motion direction	Prime mover	Origin	Insertion
Brow
Furrowing brow	Skin of the scalp	Inductive	Occipitofrontalis, frontal belly	Epicraneal aponeurosis	Underneath the skin of the forehead
Unfurrowing brow	Skin of the scalp	Posterior	Occipitofrontalis, occipital belly	Occipital bone; mastoid process (temporal os)	Epicraneal aponeurosis
Lowering eyebrows (e.one thousand., scowling, frowning	Skin underneath the eyebrows	Junior	Corrugator supercilii	Frontal bone	Peel underneath the eyebrow
Nose
Flaring nostrils	Nasal cartilage (pushes nostrils open when cartilage is compressed)	Inferior compression; posterior compression	Nasalis	Maxilla	Nasal bone
Oral fissure
Raising upper lip	Upper lip tissue	Elevation	Levator labii superioris	Maxilla	Underneath skin at the corners of the mouth; orbicularis oris
Lowering lower lip	Lower lip	Depression	Depressor labii inferioris	Mandible	Underneath peel of the lower lip
Opening oral cavity and sliding lower jaw left and right	Lower jaw	Depression, lateral	Depressor angulus oris	Mandible	Underneath peel at the corners of the oral cavity
Smiling	Corners of the mouth	Lateral top	Zygomaticus major	Zygomatic os	Underneath skin at the corners of the mouth (dimple area); orbicularis oris
Shaping of lips (as during speech)	Lips	Multiple	Orbicularis oris	Tissue surrounding the lips	Underneath skin at the corners of the oral fissure
Lateral movement of cheeks (e.m., sucking on a straw; as well used to compress air in mouth while blowing)	Cheeks	Lateral	Buccinator	Maxilla, mandible; sphenoid bone (via pterygomandibular raphae)	Orbicularis oris
Pursing of lips by straightening them laterally	Corners of the rima oris	Lateral	Risorius	Fascia of the parotid salivary gland	Underneath skin at the corners of the rima oris
Protrusion of lower lip (due east.g, pouting expression)	Lower lip and the skin of the mentum	Protraction	Mentalis	Mandible	Underneath skin of the chin
Raising upper lip	Upper lip	Meridian	Levator labii superioris	Maxilla	Underneath pare at the corners of the mouth; orbicularis oris

Muscles That Move the Optics

The movement of the eyeball is under the control of theextrinsic eye muscles, which originate outside the heart and insert onto the outer surface of the white of the heart. These muscles are located inside the eye socket and cannot be seen on whatever role of the visible eyeball (Figure ii and Tabular array 2). If you have ever been to a doc who held up a finger and asked you to follow it upward, down, and to both sides, he or she is checking to make sure your center muscles are acting in a coordinated pattern.

Effigy 2. Muscles of the Eyes. (a) The extrinsic eye muscles originate outside of the middle on the skull. (b) Each musculus inserts onto the eyeball.

Table 2. Muscles of the Eyes
Move	Target	Target movement management	Prime number mover	Origin	Insertion
Moves optics up and toward nose; rotates eyes from 1 o'clock to 3 o'clock	Eyeballs	Superior (elevates); medial (adducts)	Superior rectus	Common tendinous band (band attaches to optic foramen)	Superior surface of eyeball
Moves optics down and toward olfactory organ; rotates eyes from half-dozen o'clock to three o'clock	Eyeballs	Inferior (depresses) medial (adducts)	Inferior rectus	Common tendinous rind (band attaches to optic foramen)	Inferior surface of eyeball
Moves eyes away from nose	Eyeballs	Lateral (abducts)	Lateral rectus	Common tendinous ring (ring attaches to optic foramen)	Lateral surface of eyeball
Moves optics toward nose	Eyeballs	Medial (adducts)	Medial rectus	Common tendinous ring (ring attaches to optic foramen)	Medial surface of eyeball
Moves eyes up and away from nose; rotates eyeball from 12 o'clock to 9 o'clock	Eyeballs	Superior (elevates; lateral (abducts)	Inferior oblique	Flooring of orbit (maxilla)	Surface of eyeball between junior rectus and lateral rectus
Moves optics down and away from nose; rotates eyeball from 6 o'clock to nine o'clock	Eyeballs	Superior (elevates); lateral (abducts)	Superior oblique	Sphenoid bone	Surface of eyeball between superior rectus and lateral rectus
Opens optics	Upper eyelid	Superior (elevates)	Levator palpabrae superioris	Roof of orbit (sphenoid os)	Skin of upper eyelids
Closes eyelids	Eyelid skin	Compression along superior–inferior axis	Orbicularis oculi	Medial bones composing the orbit	Circumference of orbit

Muscles That Movement the Lower Jaw

In anatomical terminology, chewing is calledmastication. Muscles involved in chewing must exist able to exert plenty pressure to seize with teeth through and then chew nutrient earlier information technology is swallowed (Figure 3 and Table three). The masseter musculus is the main muscle used for chewing because it elevates the mandible (lower jaw) to shut the mouth, and it is assisted past thetemporalis muscle, which retracts the mandible. You can experience the temporalis move past putting your fingers to your temple as you chew.

Figure iii. Muscles That Move the Lower Jaw. The muscles that move the lower jaw are typically located within the cheek and originate from processes in the skull. This provides the jaw muscles with the big amount of leverage needed for chewing.

Tabular array 3. Muscles of the Lower Jaw
Movement	Target	Target motion management	Prime mover	Origin	Insertion
Closes mouth; aids chewing	Mandible	Superior (elevates)	Masseter	Maxilla arch; zygomatic curvation (for master)	Mandible
Closes rima oris; pulls lower jaw in under upper jaw	Mandible	Superior (elevates); posterior (retracts)	Temporalis	Temporal bone	Mandible
Opens rima oris; pushes lower jaw out under upper jaw; moves lower jaw side-to-side	Mandible	Inferior (depresses); posterior (protracts); lateral (abducts); medial (adducts)	Lateral pterygoid	Pterygoid process of sphenoid bone	Mandible
Closes oral cavity; pushes lower jaw out under upper jaw; moves lower jaw side-to-side	Mandible	Superior (elevates); posterior (protracts); lateral (abducts); medial (adducts)	Medial pterygoid	Sphenoid os; maxilla	Mandible; temporo-mandibular joint

Although the masseter and temporalis are responsible for elevating and endmost the jaw to suspension food into digestible pieces, themedial pterygoi andlateral pterygoid muscles provide assistance in chewing and moving food inside the mouth.

Muscles That Move the Tongue

Although the tongue is obviously important for tasting food, it is also necessary for mastication, deglutition (swallowing), and voice communication (Effigy four and Tabular array 4). Because it is then moveable, the tongue facilitates complex spoken language patterns and sounds.

Figure four. Muscles that Move the Tongue

Table 4. Muscles for Tongue Movement, Swallowing, and Spoken language
Motion	Target	Target motion management	Prime mover	Origin	Insertion
Tongue
Moves the tongue down; sticks tongue out of the mouth	Tongue	Inferior (depresses); anterior (protracts)	Genioglossus	Mandible	Tongue undersurface; hyoid os
Moves tongue up; retracts the tongue back into the mouth	Tongue	Superior (elevates); posterior (retracts)	Styloglossus	Temporal bone (styloid process)	Tongue undersurface and sides
Flattens tongue	Tongue	Junior (depresses)	Hyoglossus	Hyoid bone	Sides of natural language
Bulges tongue	Natural language	Superior (superlative)	Palatoglossus	Soft palate	Side of tongue
Swallowing and speaking
Raises the hyoid bone in a way that likewise raises the larynx, allowing the epiglottis to cover the glottis during deglutition; also assists in opening the oral fissure by depressing the mandible	Hyoid bone; larynx	Superior (elevates)	Digastric	Mandible; temporal bone	Hyoid os
Raises and retracts the hyoid os in a way that elongates the oral fissure during deglutition	Hyoid bone	Superior (elevates); posterior (retracts)	Stylohyoid	Temporal bone (styloid procedure)	Hyoid bone
Raises the hyoid os in a manner that presses the tongue confronting the roof of the mouth, pushing nutrient back into the throat during deglutition	Hyoid bone	Superior (elevates)	Mylohyoid	Mandible	Hyoid bone; median raphe
Raises and moves the hyoid bone forrad, widening the pharynx during deglutition	Hyoid bone	Superior (elevates); anterior (protracts)	Geniohyoid	Mandible	Hyoid bone
Retracts the hyoid bone and moves it down during later phases of deglutition	Hyoid bone	Inferior (depresses); posterior (retracts)	Omohyoid	Scapula	Hyoid os
Depresses the hyoid bone during swallowing and speaking	Hyoid os	Junior (depresses)	Sternohyoid	Clavicle	Hyoid bone
Shrinks altitude between thyroid cartilage and the hyoid os, assuasive production of loftier-pitch vocalizations	Hyoid os; thyroid cartilage	Hyoid os: inferior (depresses); thyroid cartilage: superior (elevates)	Thyrohyoid	Thyroid cartilage	Hyoid bone
Depresses larynx, thyroid cartilage, and hyoid bone to create different vocal tones	Larynx; thyroid cartilage; hyoid bone	Junior (depresses)	Sternothyroid	Sternum	Thyroid cartilage
Rotates and tilts caput to the side and forward	Skull; cervical vertebrae	Individually: medial rotation; lateral flexion; bilaterally; anterior (flexes)	Sternocleidomastoid; semispinalis capitis	Sternum; clavicle	Temporal bone (mastoid process); occipital bone
Rotates and tilts the caput to the side and backwards	Skull; cervical vertebrae	Individually: lateral rotation; lateral flexion; bilaterally: anterior (flexes)	Splenius capitis; longissimus capitis	Sternum; clavicle	Temporal bone (mastoid process); occipital bone

Natural language muscles can exist extrinsic or intrinsic. Extrinsic tongue muscles insert into the tongue from outside origins, and the intrinsic tongue muscles insert into the natural language from origins within it. The extrinsic muscles move the whole tongue in dissimilar directions, whereas the intrinsic muscles allow the natural language to change its shape (such equally, crimper the tongue in a loop or flattening it).

The extrinsic muscles all include the word root glossus (glossus = "tongue"), and the muscle names are derived from where the muscle originates. Thegenioglossus (genio = "mentum") originates on the mandible and allows the tongue to movement down and forward. Thestyloglossus originates on the styloid bone, and allows upwards and astern motion. Thepalatoglossus originates on the soft palate to elevate the back of the tongue, and thehyoglossus originates on the hyoid os to motion the tongue downward and flatten it.

Everyday Connections: Anesthesia and the Natural language Muscles

Before surgery, a patient must exist made gear up for full general anesthesia. The normal homeostatic controls of the body are put "on hold" and so that the patient tin can exist prepped for surgery. Control of respiration must be switched from the patient'south homeostatic command to the control of the anesthesiologist. The drugs used for anesthesia relax a majority of the body's muscles.

Amidst the muscles afflicted during full general anesthesia are those that are necessary for breathing and moving the tongue. Under anesthesia, the tongue tin relax and partially or fully cake the airway, and the muscles of respiration may not move the diaphragm or chest wall. To avoid possible complications, the safest procedure to use on a patient is called endotracheal intubation. Placing a tube into the trachea allows the doctors to maintain a patient's (open up) airway to the lungs and seal the airway off from the oropharynx. Post-surgery, the anesthesiologist gradually changes the mixture of the gases that go on the patient unconscious, and when the muscles of respiration brainstorm to function, the tube is removed. It all the same takes well-nigh xxx minutes for a patient to wake up, and for breathing muscles to regain command of respiration. Later surgery, most people have a sore or scratchy throat for a few days.

Muscles of the Anterior Cervix

The muscles of the anterior cervix assist in deglutition (swallowing) and speech by controlling the positions of the larynx (vocalism box), and the hyoid bone, a horseshoe-shaped bone that functions every bit a solid foundation on which the natural language can motion. The muscles of the neck are categorized co-ordinate to their position relative to the hyoid os (Figure 5).Suprahyoid muscles are superior to it, and the infrahyoid muscles are located inferiorly.

Figure 5. Muscles of the Anterior Neck. The anterior muscles of the neck facilitate swallowing and oral communication. The suprahyoid muscles originate from higher up the hyoid os in the chin region. The infrahyoid muscles originate beneath the hyoid bone in the lower cervix.

The suprahyoid muscles raise the hyoid os, the floor of the rima oris, and the larynx during deglutition. These include thedigastric musculus, which has anterior and posterior bellies that piece of work to elevate the hyoid bone and larynx when ane swallows; information technology also depresses the mandible. Thestylohyoid muscle moves the hyoid os posteriorly, elevating the larynx, and themylohyoid muscle lifts information technology and helps press the natural language to the top of the oral fissure. Thegeniohyoid depresses the mandible in addition to raising and pulling the hyoid bone anteriorly.

The strap-like infrahyoid muscles generally depress the hyoid bone and control the position of the larynx. Theomohyoid muscle, which has superior and inferior bellies, depresses the hyoid bone in conjunction with thesternohyoid andthyrohyoid muscles. The thyrohyoid muscle also elevates the larynx's thyroid cartilage, whereas thesternothyroid depresses it to create different tones of vocalisation.

Muscles That Movement the Head

The head, fastened to the top of the vertebral column, is balanced, moved, and rotated by the neck muscles (Table five). When these muscles human action unilaterally, the head rotates. When they contract bilaterally, the caput flexes or extends. The major muscle that laterally flexes and rotates the head is thesternocleidomastoid. In addition, both muscles working together are the flexors of the caput. Place your fingers on both sides of the neck and plough your caput to the left and to the right. You will feel the move originate in that location. This muscle divides the cervix into anterior and posterior triangles when viewed from the side (Figure 6).

Figure 6. Posterior and Lateral Views of the Cervix. The superficial and deep muscles of the neck are responsible for moving the head, cervical vertebrae, and scapulas.

Table v. Muscles That Move the Head
Movement	Target	Target motility direction	Prime mover	Origin	Insertion
Rotates and tilts head to the side; tilts head forward	Skull; vertebrae	Individually: rotates caput to opposite side; bilaterally: flexion	Sternocleidomastoid	Sternum; clavicle	Temporal bone (mastoid process); occipital bone
Rotates and tilts head backward	Skull; vertebrae	Individually: laterally flexes and rotates head to same side; bilaterally: extension	Semispinalis capitis	Transverse and articular processes of cervical and thoracic vertebra	Occipital bone
Rotates and tilts head to the side; tilts head backward	Skull; vertebrae	Individually: laterally flexes and rotates head to aforementioned side; bilaterally: extension	Splenius capitis	Spinous processes of cervical and thoracic vertebra	Temporal bone (mastoid procedure); occipital bone
Rotates and tilts head to the side; tilts head backward	Skull; vertebrae	Individually: laterally flexes and rotates head to same side; bilaterally: extension	Longissimus capitis	Transverse and articular processes of cervical and thoracic vertebra	Temporal bone (mastoid process)

Muscles of the Posterior Cervix and the Dorsum

The posterior muscles of the neck are primarily concerned with head movements, like extension. The back muscles stabilize and motion the vertebral cavalcade, and are grouped according to the lengths and direction of the fascicles.

Thesplenius muscles originate at the midline and run laterally and superiorly to their insertions. From the sides and the dorsum of the cervix, thesplenius capitis inserts onto the head region, and thesplenius cervicis extends onto the cervical region. These muscles can extend the head, laterally flex information technology, and rotate information technology (Figure 7).

Figure 7. Muscles of the Neck and Dorsum. The large, complex muscles of the neck and back movement the head, shoulders, and vertebral column.

Theerector spinae group forms the bulk of the muscle mass of the back and information technology is the master extensor of the vertebral column. It controls flexion, lateral flexion, and rotation of the vertebral column, and maintains the lumbar bend. The erector spinae comprises the iliocostalis (laterally placed) grouping, the longissimus (intermediately placed) group, and the spinalis (medially placed) group.

The iliocostalis group includes theiliocostalis cervicis, associated with the cervical region; theiliocostalis thoracis, associated with the thoracic region; and theiliocostalis lumborum, associated with the lumbar region. The three muscles of the longissimus group are thelongissimus capitis, associated with the head region; the longissimus cervicis, associated with the cervical region; and thelongissimus thoracis, associated with the thoracic region. The 3rd group, thespinalis grouping, comprises thespinalis capitis (head region), thespinalis cervicis (cervical region), and thespinalis thoracis (thoracic region).

Thetransversospinales muscles run from the transverse processes to the spinous processes of the vertebrae. Like to the erector spinae muscles, the semispinalis muscles in this group are named for the areas of the torso with which they are associated. The semispinalis muscles include thesemispinalis capitis, the semispinalis cervicis, and thesemispinalis thoracis. Themultifidus muscle of the lumbar region helps extend and laterally flex the vertebral cavalcade.

Of import in the stabilization of the vertebral column is thesegmental musculus group, which includes the interspinales and intertransversarii muscles. These muscles bring together the spinous and transverse processes of each sequent vertebra. Finally, thescalene muscles work together to flex, laterally flex, and rotate the head. They also contribute to deep inhalation. The scalene muscles include theanterior scalene muscle (inductive to the middle scalene), theheart scalene musculus (the longest, intermediate betwixt the inductive and posterior scalenes), and the posterior scalene muscle (the smallest, posterior to the centre scalene).

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Source: https://courses.lumenlearning.com/ap1/chapter/axial-muscles-of-the-head-neck-and-back/